Bentley - Bentley 6 1/2 litre
The 6 1/2 litre Bentley was the next model Bentley produced after the original 3 litre, in 1926. It allowed larger bodywork in more comfort and an engine capable of pulling everything along more effortlessly. The engine was in effect their stretched 4 cylinder, the six cylinders giving nearly 6.6. litres. The reason for the 9mm shorter stroke was because when the crankshaft journals were increased in diameter it was necessary to reduce the stroke to fit it in the 3 litre style crankcase cross section. To quieten the engine a different cam drive was used (on the Leyland Thomas principle), and a plate clutch over the cone type, as well as a different gearbox.
The Speed 6 was the sportier version of the 6 1/2 litre, having a different cylinder block casting for better breathing, from a manifold with twin carburettors. The cars were easily identified from their different radiators. Modified by the Works, the Speed Six brought much International and National successes, and was WO Bentleys favoured way of gaining performance, over the supercharged 4 1/2 litre model which infuriated him for the waste of time and money that could have been put to much better use.
Tyre size for the Bentley 6 1/2 litre and Speed 6 was 600x21 , and Blockley supplies the best quality tyre produced with an authentic tread. These cars never had the 700x21 size, but we list it anyway as some people like to fit these larger tyres.
